Sulfurous leuco body and process of making same.



UNITED STATES PATENT OFFICE.

BEXX-O IIOMOLKA, OF FRAXKFORT-OX-THEMAIX, AND RICHARD 'ELDE, OFHOCI-IJST-OX- I THE-MAIN, GERMANY, ASSIGXORS TO FARBWERKE VORM. MEISTERLUCIUS & BRIFNING,

OF H O CHS-T-ON-THEJIAIX, GERMAXY, A CORPORATIOX OF GERMANY.

SULFURGUS LEUCO BODY AND PROCESS OF MAKING SAME.

Specification of Letters Patent.

Patented July 21, 1908.

Application filed February 5, 1907. Seriaf No. 355,8'75.

. To all whom it may concern:

Be it known that we, Bnxn'o HOMOLKA,

Ph. 1)., and RICHARD WELDE, Ph. 1)., chemists, citizens of the Empire ofGermany, and re siding at Frankfort-on-the-Main and Hochst-'on-the-Main, Germany, respectively, have invented certain new anduseful Improvements in Making Sulfurous Leuco Bodies, of which thefollowing is a specification.

lVe' have found that alpha-oxythionaph thenes having the generalformula;

C*(OH) (1) CO R I /CH. or R{ v oH2 h S S or their carboxylic acids 1d-OH (1) 00 v R c coon 01' R{ cn-coorr by other elements or groups.

Example 10 parts by weight of alpha-oxythionaphthene or the equivalentquantity of alpha 'oxythionaphthene carboxylic acid are heated withabout 100 parts by weight of sodium thiosulfate (Na. ,S O +5H,O) or thecorresponding quantity of another alkaline or alkalineearths'thiosulfate, and 100-150 parts by weight-of industrial glycerinto about 130 C. without access of air, till no further thioindoXyl canbe traced. The. mass is allowed to cool and is diluted with water,

the leuco-body formed is filtered, washed with water and made into apaste or dried in a vacuum. For theafore said alpha-oxythionaphthene 0ra1'ha-oxythionaphthene carboxylic acid any 0t er homologous or sub'stituted alha-oxythionaphthene or alphaoxythionap ithenecarboxylicacids may be treated in like manner and yield thus thehomologous and substituted leuco bodies.

Y The sulfurous leuco bodies thus obtained are colorless, not fusiblewithout decomposing and little soluble in water. They are readilysoluble in alcohol, wood spirit, acetone and in dilute caustic alkalies.kaline' solution, when exposed to the air, rapidly separates thesulfurous dyest-uif.

Having now described our invention what we claim is:

1. The herein described process of making sulfurous leuco bodies, whichconsists in heating alphaeoxythionaphthenes with glycerin andthiosulfates soluble in water to temperatures above 100 C. 1

The al 7 2. The herein describedprocess of making sulfurous leucobodies, which consists in heating alpha-oxythionaphthene carboxylicacids with glycerin and thiosulfates soluble in water to temperaturesabove 100 C.

3. As new product, a sulfurous leuco-body being colorless, littlesoluble in water, readily soluble in alcohol, wood spirit, acetone anddilute caustic alkalies, not fusible without posed to the air,separates'the red to redrown dyestuff.

In testimony, that we claim the foregoing as our-invention, we havesigned our names in presence of two subscribing witnesses.

BENNO HOMOLKA.

I I RICHARD VVELDE. Witnesses:

JEAN GRUND, OARL GBUND.

, decomposing; the alkaline solution, when eX-

